QAB 6.7 Aftercooler servicing

[Brad Arrington]

I started to take apart the aftercooler in my QSB 6.7 480 for servicing. I shredded an impeller and knew I needed to clean it out. This is my first foray into aftercoolers and Ihave some questions.

– There is a rubber strip on the inside of each of the end caps. Upon disassembly the neither strip was attached to the cap, and they are both too long to fit back into the rib. Is this normal?

– Can the core be removed from the housing with it still attached to the engine? My initial plan was to remove the entire aftercooler but the lower recessed bolts are being very hard to remove.

– What’s the best way to remove the core? It was assembled with Alco metalube, but wasn’t budging by hand.

– On upper half of the aft side there is material on the tubes. It looks kind of like sand, but if I rub it between my fingers it smooshes. What it is?

– I removed the exhaust tube from the turbo. Do I need a new gasket or can I reassemble as is?

Pic attached.

Topic

[Brad Arrington]

That’s not my exhaust tube

Sorry, I mis-labeled. That’s not the exhaust tube; it’s the air crossover tube from the bottom of the turbo that feeds intake air to the aftercooler.

Anyway, I do need to replace the o-ring since it was disassembled? The manuals I’ve looked at on QuickServer aren’t clear on this point and I can’t find a part number for the o-ring either.

[Author]

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